Circular building structure and method of constructing the same

ABSTRACT

A circular building structure includes a floor, a cylindrical wall extending upwardly from the floor, and a roof mounted on top of the cylindrical side wall. The roof is constructed of a plurality of roof beams which are supported by and extend radially and upwardly from a perimeter of the cylindrical wall toward the center to form a peak having a cylindrical beam tube disposed therein. A plurality of flanges are attached to an outer wall of the beam tube to support the upper inner end of each roof beam and brackets are mounted to the top of the side wall to support the lower ends of the roof beams. A circular band extends around the perimeter of and is attached to the upper end of the circular wall. The structure may be elevated above ground level and a walkway constructed all around the perimeter thereof at a floor level.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to building structures. More particularly, the present invention relates to a circular building structure of sufficient strength so as to be capable of withstanding hurricane force winds and which may be used in residential housing and a method of constructing the structure.

2. Description of the Related Art

Circular dwellings are well known as evidenced by U.S. Pat. No. 6,722,091 (Leslie) and U.S. Pat. No. 2,256,050 (Hansen).

Leslie discloses a circular house which includes at least one wall panel placed under tension by bending the wall panel from a flat form to a curved form. The tension is intended to provide rigidity and strength to the wall panel. A preferred form of the house includes two tensioned wall panels with the concave faces of the wall panels confronting each other such that a generally circular residential house is formed. A counter to oppose the tension engages the wall panels and may include a roof or rafter support network, a portion of the floor or floor support, the wall panels themselves where the end edges of the wall panels are engaged to each other, or stainless steel straps running about the wall panels. As disclosed by Leslie in FIG. 17C thereof, the roof includes a central ring 76 having vertical fins or brackets 390 to which the inner ends 56 of the radial beams 50 of the roof are attached.

A disadvantage of the central ring 76 as taught by Leslie is that the only force opposing the force produced by the tension in the structure is the vertically disposed vertical fins or brackets. Particularly, the tension causes extremely high shearing forces to be applied to the fastener which attaches a radial beam 50 to the vertical fin or bracket 390. Thus, forces produced by the tension in the structure can bend, or break the vertical fins or brackets 390 or the fasteners that attach the radial beams 50 to the vertical fins or brackets 390, thereby causing the structure to become misshapen or possibly collapse.

The circular one-story dwelling as disclosed by Hansen has a cylindrical outer wall joined to a cylindrical foundation wall and a ventilator equipped roof construction joined to the cylindrical outer wall. The circular one-story dwelling as taught by Hansen is not a tensioned structure as in Leslie described above. However, Hansen discloses the use of a ventilator 16, as illustrated in FIG. 10 thereof, that serves to secure the rafters of the roof structure the same as the central ring 76 as disclosed by Leslie. The ventilator 16 of the roof structure of Hansen has upper and lower flanges 24 and 26, respectively, to which the upper ends of the rafters 12 of the roof structure are attached by fasteners.

A disadvantage of the ventilator 16 as taught by Hansen is the same as the central ring 76 of Leslie. Namely, the only force that can oppose tension that may be produced by the structure is provided by the upper and lower flanges 24 and 26 of the ventilator and the fasteners that attach the upper ends of the rafters 12 to the upper and lower flanges 24 and 26. Thus, the same as Leslie, the upper and lower flanges 24 and 26 can bend or break, thereby causing the structure to become misshapen or collapse.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved circular building structure of sufficient strength to be able to withstand hurricane force winds and which overcomes the disadvantages of the prior art discussed above.

The present invention achieves the above and other objects by providing a building structure such as a residential house built to withstand hurricane force winds and having a floor, a wall structure constructed on top of the floor, wherein the wall structure is formed by a plurality of curved panels which form a cylindrical shape, a roof which sits atop the wall structure, wherein the roof is formed by a plurality of beams which extend radially inwardly from the wall structure, toward the center of the cylindrically shaped wall structure, at an angle with the floor forming a peak, and a beam tube disposed in the peak to which the beams are attached. The beam tube has a cylindrical shape and has formed on its side, flanges, each of which are attached to the end of one beam. The inner ends of the beams attached to the flanges of the beam tube are cut at a slant so that they are flush with and abut against the sides of the beam tube. A plurality of spaced poles or posts may be provided at the periphery of the building which constitute part of the wall structure and which may be used to support the floor at a position elevated above a surface level. A circular band also may be provided around the wall structure.

According to the present invention any forces that may extend along the length of each beam toward the beam tube are opposed by the beam tube since the shape thereof causes it to resist compression forces. As per the present invention, the beam tube can more effectively oppose compression forces from the beams since the shape of the beam tube causes such forces to be distributed across the surface of the beam tube, thereby not concentrating such forces on the flange or on the fastener which attaches the end of the beam to the flange.

The present invention also includes various other features that add to the rigidity thereof. Further, these various features also allow the structure to withstand high, hurricane force, winds, efficiently channel water away from the structure to minimize water damage and maintain the interior of the structure dry and cause the structure to be energy efficient. These features include (1) setting the posts which form a part of the wall structure at predetermined distances from each other, (2) using tongue and groove construction to fit the floor boards of the floor to each other, (3) fixing the circular band to the top edge of the wall structure so as to prevent expansion of the wall structure due to the load of the roof, with the band being attached to each of the posts of the wall structure, (4) constructing the floor so that it tapers towards the center of the cylindrical structure to aid in water drainage, (5) providing louvers or air vents at preset locations in the floor, particularly near the center and near the periphery of the floor to aid in air circulation and ventilation, (6) constructing the windows so that they have a curved shape so as to reduce energy transmission and 7) extending the floor outwardly beyond the walls to form a circular walkway all around the structure.

These and other features and advantages of the present invention will become more apparent with reference to the following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of a circular building structure according to the present invention showing the structure elevated above a supporting surface level;

FIG. 2 is top plan view of the building structure of FIG. 1;

FIG. 3 is a top isometric view of the building structure of FIG. 1 showing the roof removed;

FIG. 4 is a side isometric view showing the building structure of FIG. 1 partially constructed;

FIG. 5 is an enlarged view showing a roof beam attached to the upper portion of the outer perimeter of the main body of the building structure;

FIG. 6 is an enlarged view showing three roof beams attached to a cylindrical beam tube prior to the roof beams being attached to the main body structure;

FIG. 7 is an enlarged view showing the manner in which roof beams are attached to flanges mounted on the cylindrical beam tube;

FIG. 8 is an enlarged view showing a roof beam attached by a bracket to the upper edge of the perimeter of the main building structure; and

FIG. 9 is an enlarged exploded view showing a portion of a roof beam and a flange for attaching the roof beam to an upright post and upper cross braces forming part of the main building structure;

FIG. 10 is an enlarged side elevational view a portion of the building showing the manner in which the studs, cross brace header and upper cross brace assembly are attached;

FIG. 11 is an enlarged top plan view of a portion of the upper cross brace assembly;

FIG. 12 is an enlarged plan view showing how an arcuate cross brace member is cut from a rectangular board; and

FIG. 13 is an enlarged side elevational view of a portion of the upper cross brace assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Applicant's invention provides an improved circular building structure suitable for a residence and other buildings and which possesses substantial strength capable of withstanding hurricane force winds. In a preferred embodiment, the circular building structure is supported above the level of a surface by a plurality of spaced posts embedded in the surface.

Shown in the drawings is a circular building structure 10 having a conically shaped roof 14 provided with a cylindrical beam tube 16 at the top thereof and having a generally cylindrical side wall 12 extending upwardly from a floor 18. Preferably the structure 10 is supported at an elevated level above a supporting surface such as ground 22 by a plurality of spaced posts 20 extending around the perimeter of the building. The posts 20 preferably are a total of 24 feet in length and are buried four feet in the ground, extend eight feet above ground to the floor level and continue for another 12 feet to form wall supports. Accordingly, the posts 20 extend from a position below ground level all the way up through to the top of the side wall 12. As will be described later, the tops of the posts 20 also serve as the mounting for the outer ends of roof beams forming the support for the roof 14. The building structures side wall preferably is curved to a 27 foot radius and therefore has a diameter of 54 feet. The structure also can be built with the floor at ground level.

As shown in FIG. 3, the cylindrical side wall 12 is comprised of a plurality of arcuate shaped panels or sections 30. The wall panels are provided with a plurality of windows 32 and one or more doors 34. The windows have the same curvature of a 27 foot radius as the side wall 12 and they are better able to withstand strong wind forces. In the embodiment shown, windows are formed entirely around the outer circumference of the side walls.

As shown in FIG. 4, the floor 18 of the building is supported by a plurality of joists 40 extending radially outwardly from the center of the building to a point beyond the perimeter of the side wall 12. In a preferred embodiment, the joists extend at least six feet beyond the outside of the sidewall 12 to support a circular walkway 44 extending all the way around the outside of the building. A railing 46 is provided all the way around the outer perimeter of the walkway as shown in FIG. 1. The joists 40 are supported by a plurality of cross beams 42 as shown in FIG. 4. Suitable stairs and/or an access ramp 96 may be provided at a suitable location leading up to the walkway 44 of the building.

The floor preferably is constructed of boards using a tongue and groove design so that the floor boards are snugly secured to each other. The floor 18 also is tapered downwardly from the outer perimeter towards the center of FIG. 3 to cause any liquid collected in the structure to drain towards the center and be discharged through a suitable drain located at the center of the floor. The floor is provided with larger ventilation openings 48 adjacent the outer edge thereof and smaller ventilation openings 50 towards the center thereof to permit air to flow freely up through the bottom of the floor to ventilate the structure. The ventilation openings 48 and 50 may be provided with louvers or other suitable means for controlling the flow of air therethrough.

The wall panels or sections 30 comprising the side wall 12 are constructed of a plurality of spaced studs 52 two inches thick and six inches wide, with two sets of studs positioned between each two poles 20, as shown in FIGS. 4, 8 and 10. As shown in FIG. 10 each set of studs is comprised of a long stud 53 and a shorter stud 55. The studs are connected by suitable cross beams such as window headers 54 and cross brace headers 56 as shown in FIG. 8. In addition, an upper cross brace assembly 58 extends all the way round the top of the side wall frame to additionally connect the studs together. Upper cross brace assembly 58 is comprised of a cross brace upper layer 59 and a cross brace lower layer 61.

Each cross brace layer is constructed of a plurality of arcuate cross brace members 57 positioned end to end as shown in FIG. 11 to form a circle. As shown in FIG. 12, each cross brace member 57 is cut in an arcuate shape from a rectangular board 51 which may be two inches thick, twelve inches wide and 10 feet long to form a cross brace member two inches thick, six inches wide and eight feet long. Each arcuate cross brace member is cut at a radius which is the same as the radius of the building. The ends of each cross brace member are cut at such an angle that, when placed end to end, they will form a circle which is the same size as the overall round structure of the building. As shown in FIG. 13, the arcuate cross brace members 57 of the cross brace upper layer 59 and the cross brace lower layer 61 are positioned relative to each other to form overlapping ends and the ends of the layer are secured to each other with suitable fasteners such as bolts 65.

A lower cross brace assembly (not shown) also is provided all around the bottom of the circular side wall 12. The lower cross brace assembly may be comprised of one layer of arcuate cross brace members secured to the joists 40 and the posts 20.

Each long stud 52 extends from the lower cross brace assembly to the lower cross brace layer 61 of the upper cross brace assembly 58. As shown in FIG. 10, the upper end of each long stud 52 may be attached to the upper cross brace assembly 58 by a metal strap 57 which extends from one side of the stud 52 and over the top of the upper cross brace assembly to the other side of the stud. Each shorter stud 53 extends from the lower cross brace assembly to a cross brace header 56. Each cross brace header 56 rests on and is supported by two of the shorter studs 53.

The outside of the circular side wall 12 is covered with a suitable band of wide material 60 at the top and a suitable band of wide material 62 at the bottom and vertical coverings 64 are provided for the posts and studs as shown in FIG. 6 to complete construction of the wall panels or sections 30.

The roof 14 is comprised of a plurality of spaced roof beams or rafters 66 which are supported by and extend radially inwardly and upwardly at an angle to the floor from the upper perimeter of the cylindrical side wall 12 towards the center of the structure to form a conical shape having a peak at the top thereof. The cylindrical beam tube 16 is disposed in the peak formed by the roof beams 66 and provides support for the upper end of each of the roof beams. As shown in FIGS. 6 and 7, the cylindrical beam tube 16 has a plurality of generally L-shaped flanges 70 attached to the outside thereof to receive the upper inner ends of the roof beams 66. Each flange 70 has a bottom wall 72 angled downwardly at an angle the same as the upward angle of each roof beam so that the roof beam may be securely fastened to each flange by suitable means such as bolts or screws. The inner end of each roof beam 66 is cut at a slant so that it can fit parallel to and flush against the side of the circular beam tube 16. With this construction, the force transmitted along a roof beam 66 is transmitted to the cylindrical beam tube over a large area and the circular configuration of the beam tube further spreads any force around a perimeter of a beam tube to evenly dissipate such forces without risk of damaging the beam tube.

The circular beam tube 16 also may be provided with a suitable fan such as a three speed electric fan 74 as shown in FIG. 6 to assist in ventilating the structure upon its completion.

The lower end of each roof beam is attached to the upper edge of the cylindrical side wall 12 and one of the posts 20 by a bracket 76. As shown in FIG. 9, each bracket 76 has an outer flange 78 and an inner flange 76 as well as a side flange 82 and an intermediate top surface 84 slanted at the same angle as the downward angle of a roof beam 66. A plurality of bolts 86 extend through holes in the bracket 76 to bolt the flange to post 20 as well as to a roof beam 66. The bracket 76 therefore provides a very secure connection of the lower end of each roof beam to the cylindrical side wall 12 and particularly to each post 20. Moreover, the weight of each of the roof beams 66 and a roof covering supported by the roof beams bears down primarily on the posts 20 and therefore little downward force and outward force is exerted on the wall sections by the roof structure, including the roof beams.

After the roof beams have all been installed and securely connected to the cylindrical beam tube and the post 20, a suitable roof covering 90 is put on the roof beams and is supported thereby.

Finally, circular band 92 of metal is mounted around the outside of the upper end of the circular wall 12. The band is securely and tightly wrapped all the way around the circular wall 12 and may be attached to itself at the ends by either welding or by overlapping and bolting the two ends together or by any other suitable means. Metal band 92, as shown in FIG. 5 is attached to each of the brackets 76 by suitable means such as welding or by bolts. The circular band 92 may be of any suitable metal such as steel. The circular band 92 reinforces the strength of the side wall and by being attached to the brackets 76, forces extending downwardly along the rafters are transferred through the brackets to the posts 20 and the forces then travel down the posts 20 to the surface. This construction provides a strong side wall which permits the side wall to withstand strong forces such as hurricane winds.

In constructing the building structure of the present invention, a plurality of posts are mounted in spaced relationship in a circular configuration and are firmly and securely implanted in a surface such as a ground surface. Preferably at least seventeen posts are mounted in the surface. A plurality of joists and other floor supporting members are then mounted at an elevated level above the surface and are supported by the posts. A floor is then attached to the floor supporting members and is constructed of boards having a tongue and groove interfitting relationship. The circular wall is then constructed having a plurality of curved or arcuate panels or sections. Windows having the same curvature as the wall panels are then mounted in at least some of the wall panels. At least three evenly spaced roof beams are attached to a cylindrical beam tube and the three roof beams and the cylindrical beam tube are then temporarily supported at a position above the top of the cylindrical wall. Each of the three beams are then secured to the top of the wall by brackets. Subsequently, the remainder of the roof beams are installed and a circular band or strap is mounted to extend all around the perimeter of the upper edge of the circular wall. The circular band is attached to each of the brackets supporting the lower ends of the roof beams. A roof covering then is installed over the roof beams.

Applicant's circular building structure thus provides a strong building suitable for use as a residence capable of withstanding strong forces such as hurricane wind forces. The circular walls and windows function to spread any stress around the sides of the building and forces are not concentrated at any one point. Moreover, by elevating the structure above ground, the structure also is suitable for use along a sea coast to keep it above water. The ventilation openings in the floor and the cylindrical beam tube provided with a fan in the top create a good air circulation path to keep the building cool.

Numerous other modifications and adaptations of the present invention will be apparent to those skilled in the art and thus, it is intended by the following claims to cover all such modifications and adaptations which fall within the true spirit and scope of the invention. 

1. A circular building structure comprising: a) a floor; b) a cylindrical side wall comprised of a plurality of curved panels extending upwardly from said floor; c) a roof mounted on top of said wall; d) said roof comprising a plurality of roof beams which are supported by and extend radially inwardly and upwardly at an angle to said floor from a perimeter of said cylindrical wall toward a center of said structure to form a peak; e) a cylindrical tube disposed in said peak; f) a plurality of flanges attached to an outer wall of said beam tube with one flange being provided for each roof beam and having a bottom wall angled downwardly at an angle the same as the upward angle of each roof beam; g) an inner end of each roof beam being formed at a slant so that it abuts against and is flush with the outer wall of said beam tube when the inner end of the roof beam is mounted in said flange; and h) a circular band extending around the perimeter of and attached to the circular wall.
 2. A circular building structure according to claim 1 which further includes a plurality of spaced posts forming part of said circular wall and extending upwardly from a supporting surface and wherein said floor is supported by said poles at a position elevated above said surface.
 3. A circular building structure according to claim 2 wherein said floor extends outwardly from the perimeter of said circular wall to form a walkway there around.
 4. A circular building structure according to claim 2 wherein said floor is tapered downwardly toward the center thereof.
 5. A circular building structure according to claim 4 which further includes ventilation openings at spaced locations in said floor.
 6. A circular building structure according to claim 1 which further includes a plurality of windows in said cylindrical wall, said windows being curved at a same curvature as said cylindrical wall.
 7. A circular building structure according to claim 2 which further comprises a bracket attaching each roof beam to one of said posts.
 8. A circular building structure comprising: a) a floor; b) a cylindrical side wall comprised of a plurality of curved panels extending upwardly from said floor; c) a plurality of windows in said cylindrical wall, said windows being curved at a same curvature as said cylindrical wall; d) a plurality of spaced posts forming part of said circular wall and extending upwardly from a supporting surface and wherein said floor is supported by said poles at a position elevated above said surface; e) a roof mounted on top of said wall; f) said roof comprising a plurality of roof beams which are supported by and extend radially inwardly and upwardly at an angle to said floor from a perimeter of said cylindrical wall toward a center of said structure to form a peak; g) a bracket attaching each roof beam to one of said posts; h) a cylindrical tube disposed in said peak; i) a plurality of flanges attached to an outer wall of said beam tube with one flange being provided for each roof beam and having a bottom wall angled downwardly at an angle the same as the upward angle of each roof beam; j) an inner end of each roof beam being formed at a slant so that it abuts against and is flush with the outer wall of said beam tube when the inner end of the roof beam is mounted in said flange; and k) a circular band extending around the perimeter of and attached to the circular wall.
 9. A method of constructing a circular building structure comprising: a) mounting a plurality of spaced posts in a circular configuration on a supporting surface; b) constructing a floor supported by said posts and elevated above said surface; c) constructing a cylindrical side wall comprised of a plurality of curved panels extending upwardly from said floor d) temporarily disposing a cylindrical tube centrally of said side wall at an elevation above the top of said side wall; e) mounting a plurality of roof beams which are supported at their upper end by said cylindrical tube and which are supported at their lower ends by brackets attached to said posts at the top thereof to form a conically shaped roof extending radially inwardly and upwardly at an angle to said floor from a perimeter of said cylindrical wall to said cylindrical tube; each of said roof beams being formed at a slant at its inner end so that it abuts against and is flush with an outer wall of said beam tube and attached thereto, and f) securing a circular band all the way around a perimeter of the upper end of said circular wall and attaching said circular band to the brackets attaching said roof beams to said circular wall. 